Formaldehyde and Indoor Air Quality

Alex Manning, Clean Air Advice
June 2006

Formaldehyde is a colorless yet pungent-smelling gas that is widely used in manufactured building materials and household products. Formaldehyde's most common use is as an adhesive resin in pressed woods. There are two types of formaldehyde resins: urea formaldehyde (UF) is used mainly in indoor construction and phenol formaldehyde (PF), which is used in exterior grade materials.

Building materials made with formaldehyde resins emit formaldehyde gas. Of the types of resins, the phenol formaldehyde (PF) resin emits at much lower levels than the urea formaldehyde (UF) resin. Some products that include these resins are particleboard used as sub-flooring, fiberboard used in furniture, plywood used as wall panels and UF foam insulation. As these products age they emit lower levels of formaldehyde but still cause poor indoor air quality. Other sources of formaldehyde gas include incomplete combustion, environmental tobacco smoke, and burning wood and natural gas.

Normal levels of formaldehyde, both indoors and outdoors, are less than 0.06ppm (parts per million). When present at levels at or above 0.1ppm your indoor air quality may be a cause for concern. At these levels exposure can cause watery eyes; burning or the eyes, nose and throat; coughing; wheezing; nausea; skin rashes and other irritations. In lab tests, formaldehyde has been proven to cause cancer in animals and may cause cancer in humans. Risks associated with formaldehyde correlate to the duration and concentration of exposure. While formaldehyde-measuring kits are available for home use, when accuracy is an issue only a trained professional should test for concentration levels.

There are several ways in which you can improve your indoor air quality with respect to formaldehyde gas. When selecting building materials, or any pressed wood product, purchase those labeled as low emitting or products made using PF resins. Formaldehyde levels will increase after bringing new sources into your home. Increasing ventilation can help reduce these high concentrations in your indoor air. Avoid using formaldehyde foam insulation all together if possible. Enclose unfinished pressed-wood surfaces in laminate or sealant. Maintaining a moderate temperature and humidity level in your home will also help reduce formaldehyde emissions as the emission rate is accelerated by heat and moderately dependent on humidity levels.

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